High-speed wire-stranding machine

ABSTRACT

A high-speed wire-stranding machine with a low-noise factor in which the rotor comprising a cylindrical framework is equipped with one or more axially slidable sleeves or closure members adapted to enclose the openings required in the periphery of the rotor for exchanging one or more feed spools mounted within the cylindrical framework, preferably with locking means to hold said sleeves or closure members in their closed position during operation of the machine.

United States Patent Berges [4 1 Jan.25, 1972 1 HIGH-SPEEDWIRE-STRANDING MACHINE [72] Inventor:

[73] Assignee:

Dietrich Berges, Marienheide, Germany Barmag Barmer MaschinenfabrikAktiengesellschaft, Wuppertal, Germany 221 Filed: Apr. 27, 1970 211Appl.No.: 32,040

[30] Foreign Application Priority Data May 3, 1969 Germany ..P 19 22745.3

[52] U.S. Cl ..57/58.3 [51] Int. Cl. .D07b 3/04 [58] Fieldot' Search..57/58.3, 5832, 58.34

[56] References Cited UNITED STATES PATENTS 1,870,290 8/1932 Larmuth..57/58.3 2,371,523 3/1945 Jones ...57/58.34 2,671,303 3/1954 Pearce..57/58.3 X

FOREIGN PATENTS OR APPLICATIONS 770,776 3/1957 Great Britain ..57/58.32921,626 3/1963 Great Britain ..57/S8.32

OTHER PUBLICATIONS German Printed Publication #l,003,096 2/1957, WernerCramer German Printed Publication #1,112,428, 8/1961, Max .SteinleinPrimary Examiner- Donald E. Watkins Attorney-Johnston, Root, O'Keeffe,Keil, Thompson & Shurtleff [5 7] ABSTRACT A high-speed wire-strandingmachine with a low-noise factor in which the rotor comprising acylindrical framework is equipped with one or more axially slidablesleeves 0r closure members adapted to enclose the openings required inthe periphery of the rotor for exchanging one or more feed spoolsmounted within the cylindrical framework, preferably with locking meansto hold said sleeves or closure members in their closed position duringoperation ofthe machine.

6 Claims, 3 Drawing Figures PATENTED JANZSISYZ 35316392 FIG. 3

INVEN'I'UR: DIETRICH BERGES ATT'YS 1 HIGH-SPEED WlRE-STRANDING MACHINEin general, the present invention relates to well-known strandingmachines of the type in which individual wires or stranded componentsare drawn from their spools and brought together and twisted into astranded product by means of at least one so-called routing tube orcylindrical rotor, at least one feed spool being arranged within therotor which must have one or more openings or so-called zones" forinstalling and removing the feed spools.

These twisting or stranding machines are usually installed for theproduction of strands or cables composed of steel, nonferrous metalalloys, light alloys or the like, or even for the twisting together ofsuitable metal wires or cords in combination with textile materials,such as threads, yarns, cords or the like. Stranding machines aregenerally constructed in such a manner as to essentially require atleast one or several tubularshaped rotating bodies, each of which isidentified herein as a rotor. The number of such rotors generallycorresponds to the number of wires or cords to be added or twistedaround a core wire which passes in sequence through each rotor where oneor more individual wires or cords are added and twisted in a singleoperation. As a rule, the rotors are arranged one behind the other on acommon axis of rotation in order to minimize the number of turns orbends in the path of the running strand as it is fabricated. For reasonsof stability, each rotor normally contains not more than three feedspools so that the axial length of the rotor can be kept as short aspossible and also to avoid intermediate accumulation or storage ofextensive lengths of the wires, cords or strands running through therotor.

In the first instance, the core wire may be a single wire around whichindividual wires are subsequently wound or twisted to fabricate astrand. In subsequent rotors, however, the partially fabricated strandcan become the core wire for application of additional wires. On theother hand, both the core wire and the wires to be added may also be inthe form of cords or individually stranded elements. In all cases, thecore wire is generally led to the first rotor from a feed spoolrotatably mounted in a fixed position externally of the rotor with thespool normally being freely mounted for rotation as driven by thewithdrawal of the core wire therefrom, the rate of withdrawal also beinginfluenced by the rotatably driven rotor.

In conventional high-speed stranding machines for the production of wirecables or wire strands, the core wire such as a steel wire is arrangedin a path of travel which fonns an angle of less than 25 with the axisof the rotor. Under these circumstances and in spite of the wire beingcarried or driven in a rotating path or envelope through the rotor, noplying of the core wire takes place but instead the wire passes throughthe rotor without twisting. In order to avoid such twisting in therotor, it is naturally also desirable to make a suitable choice ofmaterials for each element of the rotor which comes in contact with thewire. Thus, the material in running contact with the core wire and alsothe hardness of the wire itself plays a role in preventing twisting aswell as the angle at which the core wire is conducted with reference tothe axis of rotation of the rotor.

inside of the rotor, there is located at least one feed spool forsupplying additional wire or cord to be fabricated in combination withthe core wire. This inner feed spool is generally supported in arotatably mounted cage arranged on the same axis of rotation as therotor, i.e., so that the rotor can be rotatably driven independently ofthe cage. The center of gravity of the cage is sufficiently low so thatit remains in a stationary position during rotation of the rotor. Thefeed spool in turn is rotatably supported by its spindle or shaft onthis cage, and the wire or cable to be stranded onto the core wire isdrawn off this inner feed spool. In the operation of the highspeedstranding machine, the individual wire to be stranded extends from theinner feed spool at the smallest possible angle with the axis ofrotation of the rotor and is then picked up by the rotor and driven in acircular path or envelope. In

this case, it is also desirable to provide an arrangement such that thestranding wire from the inner feed spool can emerge from the rotorwithout twisting. Depending upon the desired construction of the finalstranded product, several feed spools of the same type are arranged onebehind the other in the axial direction of the rotor with the spindlesor axes of the feed spools being approximately vertical andperpendicular to the axis of rotation of the rotor. in order to achievea stable operation, however, the rotor must not be too long, since it isotherwise impossible to suppress vibrations, especially at highrotational velocities.

At the front end of the rotor, i.e., where the core wire and one or moreadditional wires emerge, there is provided a disc plate containingradially displaced openings through which the individual wires areconducted from the rotor. These openings are generally reinforced withguide pieces, e.g., a diamond or adamantine surface. From their radiallyseparated positions in contact with the disc plate, the individual wiresor cords are conducted to a stranding point separated at an intervalfrom the disc plate, this stranding point usually consisting of a singlesleeve lined with a hard metal or diamond surface, often in two pieces.In this fixed sleeve, the wires or cords are joined into a strand whichis then drawn from the sleeve.

In order to load fully wound feed spools into and also to.

remove empty feed spools from the cage supported freely within therotatable tubular body or rotor, it is necessary to provide at least oneopening or so-called window" for each feed spool, the opening beingsufficiently large to permit easy passage of the feed spool. Also, inorder to service the machine and to facilitate the installation andremoval of feed spools from either side of the machine, two or eventhree windows or openings are preferably distributed around thecircumference of the rotor, so that a complete zone exists for each feedspool. Accordingly, it has been a practice to construct the rotor as acylindrical framework with longitudinal crosspieces or crossbarsseparating the peripheral openings in each window zone. However, thetubular cross section of the rotor is weakened by the peripheralopenings and the flexural stiffness of the tube or rotor framework isconsiderably reduced. The centrifugal forces arising during operation ofthe rotor tend to cause a certain deformation or warping of thecrossbars between the openings, and in order to maintain such distortionwithin permissible limits, one is forced to reduce the rotationalvelocity of the rotor. At the present time, the rotors of conventionalhigh-speed stranding machines can be driven at an uppermost rotationalspeed of about 2,000 to 3,000 revolutions per minute. Higher speedswould cause a serious weakening of the rotor, and the limitation onrotational velocity correspondingly prevents any increase in theproduction rate of the stranding operation.

In order to reduce the distortions of the crossbars separating theopenings of the rotor around the feed spool positions, it has beenproposed in German Pat. No. 955,035 to construct the rotor from tubeswhich telescope together and reinforce each other. It has been furthersuggested in German Auslegeschrift No. 1,003,096 that the weakness ofthe rotor cross section caused by the openings can be compensated byincreasing the wall thickness of the crossbars or other portions of therotor surrounding the openings. With this measure, it is possible tosomewhat increase the speed of the rotor and also the production rate ofthe strands in the stranding operation, but it has also been found thatthe crossbars or members surrounding the rotor openings result inincreasing noise at higher rotational velocities. At the desired higherspeeds, such noises are no longer tolerable to service personnel. Thenoise of the machine in this instance arises from the turbulence of airlayers on the edges of the crossbars. Also, this air turbulence uses upadditional energy which must be furnished by the drive motor of therotor.

One object of the present invention is to provide a highspeedwire-stranding machine in which the rotatably driven rotor has arelatively low noise factor even when operated at substantially higherspeeds as compared to conventional rotors. Another object of theinvention is to avoid any thickening of the crossbars between theperipheral openings around the feed spool positions of the rotor, whileat the same time substantially eliminating the above-noted airturbulence along the edges of such crossbars. Yet another object of theinvention is to provide an improved rotor construction which can bereadily adapted to conventional high-speed wire-stranding machines andwhich continues to permit an easy interchange of feed spools from theirnonnal positions within the rotor, e.g., as mounted in a conventionalcage structure. These and other objects and advantages of the inventionwill become more apparent upon consideration of the following detaileddisclosure.

It has now been found, in accordance with the invention, that theconventional high-speed wire-stranding machine having a rotatably drivenrotor with at least one large peripheral opening at each spool positioncan be substantially improved and the noise factor substantially reducedif the elongated cylindrical framework of the rotor is provided with atleast one cylindrically shaped closure member which is axially slidableon the rotor over the opening at each spool position to provide a sleeveconcentrically encasing the cylindrical framework during operation ofthe machine. Also, it is especially advantageous for each closure memberto be associated with a releasable locking means in order to hold thisclosure member or sleeve securely over the peripheral opening duringoperation of the machine. It is also advantageous to provide a closuremember which has a greater axial length than its associated peripheralopening in the cylindrical framework. The resulting combination of therotor structure not only permits high-speed operation with a low noisefactor but also permits the incorporation of certain safety features asdescribed more fully hereinafter.

An especially preferred embodiment of the invention is set forth in theaccompanying drawing in which:

FIG. 1 is a schematic view of a rotor unit constructed in accordancewith the invention with certain portions cut away;

FIG. 2 is an enlarged illustration of the first portion of the rotorshown in FIG. I, partly in cross section through the axis of rotation ofthe rotor; and

FIG. 3 is an enlarged cross-sectional view of a preferred tubular guideor conduit for a running wire or cable as arranged within the rotor.

Referring first to FIGS. 1 and 2, there is schematically illustrated theconventional rotor or so-called routing tube 1 which can contain severalwindow zones 2 and 3 in the form of one or more peripheral openingsaround the circumference of the rotor at different positions along itslength corresponding to the positions of feed spools 4 and 5 containedwithin the rotor. These feed spools 4 and 5 which supply the initialwire or cord to be stranded are rotatably mounted in their respectivecages 6 which in turn are arranged within the rotor by means of thepivots or rotatable bearing supports 7 and 8 located concentricallyaround the axis of rotation of the rotor. The position of the center ofgravity of each cage 6 is sufficiently displaced from the rotor axis ofrotation that the cage remains in a substantially stationary positionwhile the rotor revolves. This also means that the spindle or shaft oreach feed spool 4 and 5 will also be retained in a substantiallystationary position, preferably so that the axis of rotation of the feedspool is perpendicular to the axis of rotation of the rotor.

When the rotor 1 is at a standstill, the individual feed spools 4 and 5can be inserted or removed through the'window or peripheral opening ofeach window zone 2 and 3, respectively. Any conventional means can beused to interchangeably or removably mount a feed spool in its cage. Inorder to facilitate the interchange of feed spools, the peripheralopening or openings at each feed spool position must be sufficientlygreater than the size of the feed spools as to permit a convenient andrapid manipulation of the heavy spools as they are loaded or removedfrom the machine. In essence, this requires that the individual loadingwindows or openings must be proportionately large as measured about thecircumference of the rotor, while the width of the crossbars 9 locatedbetween individual openings in each zone must be proportionately small,i.e., as measured in the circumferential direction of the rotor ortube 1. Thus, in the conventional construction of the rotor for ahigh-speed stranding machine, it is practically essential to employrelatively narrow crossbars at relatively large spaced intervals aroundthe circumference of the rotor at each feed spool position, and althoughthese crossbars or struts provide a sufficient reinforcing framework forthe cylindrical rotor at relatively low operating speeds, they are bentoutwardly at high rotational speeds of the rotor under the influence ofcentrifugal forces and even become permanently deformed after exceedinga certain rotational velocity.

In order to avoid this deformation of the rotor framework around thefeed spool positions, the present invention provides a number of axiallyslidable or shiftable closure members such as sleeves l0 and 11 whichconcentrically surround the rotor 1. It is preferable to employ a singlesleeve for each window zone corresponding to a feed spool position. Theinner circumference of each sleeve 10 and 11 is substantially identicalto the outer uniform circumference of the rotor 1 so as to provide asnug fit while still permitting the sleeve to slide relatively easilyalong the outer circumference of the rotor. Each sleeve is thus appliedaround the peripheral openings like a snugly fitting bandage, and thiscomplete encasing or encircling of the so-called window zones by asleeve having an uninterrupted cross section effectively avoids anythickening or broadening of the crossbars 9. Moreover, these sleevesshield or block off the window zones 2 and 3 against the steadilyrecirculated air so that air turbulence is prevented at these points andthe development of noise as well as the energy requirements aresubstantially diminished. Thus, where the outside air has no access intoor through the windows or peripheral openings so as to be affected bythe rapidly rotating crossbars, there is very little if any relativemovement between stationary components of air and its rapidly rotatedcomponents. When the sleeve members according to the present inventionare in the closed position over the so-called window zones, it has beenfound that the rotational speed of the machine can be considerablyincreased while successfully reducing the development of noise to limitswhich are tolerable to service personnel.

As shown in FIG. 1, it is especially advantageous if the axiallyslidable sleeve or casing member 10 or 11 exhibits a large axial length,e.g., so as to slightly overlap the corresponding axial length of eachwindow zone 2 or 3, respectively. This not only ensures a completeenclosure of each feed spool position, but also provides overlapping orcontacting surfaces of the sleeve and rotor around the circumference forpositioning a suitable locking means to hold the sleeve in the closedposi tion. This locking of the sleeve is necessary for reasons ofsafety, and any conventional means can be used for this purpose.

For example, the sleeve can be locked in place over the window zone in avery simple manner by providing a spring arranged on the tubular body ofthe rotor or on the inside of the sleeve so as to engage into acorrespondingly arranged groove or notch in the opposing surface. Theuse of such a spring locking means 12 is shown by way of example in FIG.2. Thus, the spring and groove combination 12 can be used to lock thesleeve 10 in place when it abuts the end collar 13 which is mounted in afixed position on the rotor 1. Each sleeve can be provided with such aspring and groove combination, and other locking means may also beemployed to hold the individual sleeves in place, e.g., by using pinsinserted into bores of the rotor body so as to innerlock intocorresponding recesses of the sleeve under the influence of centrifugalforce. It is preferable to employ a locking means which can be easilyreleased, provided that the sleeve is held firmly against axial movementduring operation of the high-speed stranding machine.

Before going further into details concerning preferred features of themachine according to the invention, a brief explanation can be givenwith reference to FIG. 1 as an example of the typical operation of ahigh-speed stranding machine for the fabrication of strands or cables.As previously indicated, a plurality of feed spools such as 4 and 5 arelocated within the cylindrical framework of the rotor 1, each spoolproviding an individual wire or cord for the stranding process. Inaddition, another feed spool 14 is arranged outside of the rotor 1 andgenerally furnishes the core wire 15. This core wire 15 can be guidedover a suitable roller 16 and axially introduced through the shaft stub17 into the rotor l. The core wire is preferably conducted in accordancewith the invention so as to pass through the shaft stub 17 and collar 13at an angle to the rotor axis and then run in a tubular guide member 18mounted on an inner wall surface of the rotor framework 9 as shown morefully in FIG. 2. This tubular guide 18 extends over most of the lengthof the rotor and permits the core wire to be conducted completelythrough the rotor without in any way interfering with the operation ofthe feed spools contained within the rotor. In other words, the path ofthe core wire through the rotor completely bypasses the feed spools andis maintained free of contact of the additional wires being supplied bythe inner feed spools. This longitudinal guide tube 18 is furtherillustrated by the enlarged cross-sectional view of its feed end asshown in FIG. 3, and in accordance with a further refinement of thepresent invention, this guide tube 18 is advantageously lined on itsinner surface with a layer 19 of a hard metal or metal carbide or otherhard-surfaced and wear-resistant material such as ceramic materials orthe like. By this means, the abrasion between the core wire 15 and theinner surface of the tube 18 is substantially reduced, and this effectis exceptionally advantageous in achieving the necessary suppression ofany twisting of the core wire 15 as described more fully above.

A fresh wire 20 to be stranded is drawn off from the feed spool 4 andlikewise conducted along the wall of the rotor by means of the guidetube or conduit 21 which can be constructed in the same manner as guidetube 18, i.e., with a hard inner liner. Finally, another fresh wire 22is drawn off from the feed spool 5 (shown only in FIG. 1) and isconducted through a guide tube similar to tube 21, to the exit end ofthe rotor 1. At this exit, the rotor framework is connected to a shaftstub 23 which has openings or conduits for the individual wires suchthat the core wire 15 is drawn from the rotor 1 along its longitudinalaxis of rotation while the wires 20 and 22 are spaced radially outwardlyfrom the core wire 15 and preferably at diametrically opposite positionsof a common circle. A drive motor 24 is used in a conventional manner torapidly rotate the rotor l, e.g., by means of a drivebelt running aroundcollar 13 or by any other suitable driving connection. The three wires15, 20 and 22 can be jointly withdrawn at any desired speed from therotor l in the longitudinal direction indicated by the arrow, using anyconventional draw means, takeup means or other transporting means. Theremaining elements of the high-speed stranding machine or individualcombinations of such elements are so well known that they are notillustrated in the drawing. For example, the wires can be conductedthrough one or more additional rotors in which additional wires to bestranded are added in sequential operations, or else the wires can beconducted directly to the so-called disc plate and finally to thestranding point which is in a fixed position relative to the rotatingdisc plate. Alternatively, a few wires can be drawn from a single rotoras shown in FIG. 1 and stranded together to form a core wire which isstill sufficiently small to be passed through another rotor for theaddition of more wires onto the initially stranded core wire. These andother conventional variations can be made in the stranding processitself without affecting the function of the individual rotors accordingto the invention.

In order to safely prevent any actuation or continued rotation of therotor 1 of the stranding machine when either one or both of the sleevesl0 and 11 are no longer in their correct closed positions around thefeed spool openings or window zones 2 and 3, it is preferable to provideso-called safety contacts 25 and 26 which are actuated by theirrespective sleeves in order to switch off the current to the drive motoras supplied through the electrical line 27 which may further contain amanually operated switch 28. The line 27 is of course connected as oneline supplying current to the drive motor 24 and will be disconnected byactuation of either one of the safety contacts or similar switchingmeans 25 and 26 connected in series in this line. Any type of safetycontact or switch can be employed, and as illustrated in FIG. 2, it ispossible to arrange a spring-actuated plunger 25a or 26a, which in itsnormal extended position closes the switch and permits the drive motorto rotate the cylindrical framework of the rotor while the sleeves l0and 11 are in closed position. Once these sleeves move into an openposition, they come in contact with the plungers 25a and 26a,respectively, which are depressed to open a switch in the line 27. Itwill thus be apparent that the rotor cannot be driven unless both of thesafety contacts or switches are closed and this occurs only when bothsleeves 10 and 11 are in the correct closed position around the feedspools.

These safety contacts or safety switches 25 and 26 can additionallyserve the purpose of detecting imbalances in the rotor operation, forwhich purpose they must be arranged so closely to the outer surfaces ofthe rotor 1 that they react and cut out or trip off the electricalcurrent as soon as the vibrations of the rotor exceed a certainpredetermined value. Alternatively, this function can also be assumed bystill another switch such as 28 while providing a manual switch on themotor 24 itself.

It will be recognized from the foregoing description that the rotor ofthe invention can be very safely operated in a highspeed strandingmachine since the circuit for the drive means can only be closed wheneach sleeve or closure member has been shoved into its position over theso-called window zones. There is no way in which the machine can beoperated while the sleeves are in an open position to permit the loadingor removal of feed spools. Most importantly, of course, the

v sleeves or closure members function in such a manner as to verysubstantially reduce the noise factor of the many rotors normallyrequired in any commercial operation of stranding machines. At the sametime, very high speeds can be achieved with the rotor of the inventionwithout deforming or otherwise impairing the necessarily open frameworkstructure of the rotor. The invention thus permits much higherproduction rates with complete safety and relatively little noise. Atthe same time, however, the individual elements of the rotor are easilyassembled and placed in operation while maintaining a rapid and simpleinterchange of feed spools.

The invention is hereby claimed as follows:

1. In a high-speed wire-stranding machine in which at least one feedspool is supported within a rotatably driven rotor comprising anelongated cylindrical framework having at least one large peripheralopening at each spool position for interchanging feed spools, theimprovement which comprises at least one cylindrically shaped closuremember which is axially slidable on said rotor over the opening at eachspool position to provide a sleeve concentrically encasing thecylindrical framework during operation of the machine.

2. A wire-stranding machine as claimed in claim 1 wherein each closuremember is associated with a releasable locking means to hold it securelyover the peripheral opening during operation of the machine.

3. A wire-stranding machine as claimed in claim 1 wherein said closuremember has a greater axial length than its associated peripheral openingin the cylindrical framework.

4. A wire-stranding machine as claimed in claim 1 including safetycontact means externally of said rotor for turning off the rotatingdrive of said rotor in response to axial movement of each closure memberuncovering its associated opening.

5. A wire-stranding machine as claimed in claim 1 wherein guide tubesare mounted inside of said cylindrical framework for conducting thewires to be stranded.

6. A wire-stranding machine as claimed in claim 5 wherein said guidetubes are provided with a hard, wear-resistant inner lining.

1. In a high-speed wire-stranding machine in which at least one feedspool is supported within a rotatably driven rotor comprising anelongated cylindrical framework having at least one large peripheralopening at each spool position for interchanging feed spools, theimprovement which comprises at least one cylindrically shaped closuremember which is axially slidable on said rotor over the opening at eachspool position to provide a sleeve concentrically encasing thecylindrical framework during operation of the machine.
 2. Awire-stranding machine as claimed in claim 1 wherein each closure memberis associated with a releasable locking means to hold it securely overthe peripheral opening during operation of the machine.
 3. Awire-stranding machine as claimed in claim 1 wherein said closure memberhas a greater axial length than its associated peripheral opening in thecylindrical framework.
 4. A wire-stranding machine as claimed in claim 1including safety contact means externally of said rotor for turning offthe rotating drive of said rotor in response to axial movement of eachclosure member uncovering its associated opening.
 5. A wire-strandingmachine as claimed in claim 1 wherein guide tubes are mounted inside ofsaid cylindrical framework for conducting the wires to be stranded.
 6. Awire-stranding machine as claimed in claim 5 wherein said guide tubesare provided with a hard, wear-resistant inner lining.